低山丘陵区土地利用方式对土壤质量的影响——以河北省遵化市为例

Abstract

通过调查河北省遵化市低山丘陵区油松林、板栗、草地和坡耕地等典型土地利用方式对土壤养分和土壤容重的影响。土壤取样取土壤表层 0～ 2 0 cm。结果表明 ,森林的砍伐以及随后的耕种显著增加了土壤容重并降低了大部分土壤养分。和林地相比 ,草地、当年开垦的农地、板栗和耕种 3年的农地容重分别增加了 1 3.3% ,1 4.2 % ,2 7.5% ,39.7%。除全磷外 ,板栗和耕种 3年的农地土壤养分有显著下降 ,和林地相比 ,板栗有机质减少了 60 .7% ,全氮减少了 35.6% ,全钾减少了 2 1 .3% ,速效钾减少了 57% ;耕种 3年的农地土壤有机质、全氮、全钾和速效钾则分别减少了 62 .9% ,52 .6% ,31 %和 60 %。土壤退化指数的计算结果表明板栗和耕种 3年的农地土壤发生了较为严重的退化。

How to use rationally the lands in hilly areas is very important to preserve soil quality and develop sustainable land use model. This study was undertaken to evaluate the effects of land use on soil nutrients and soil bulk density in the hilly area of Zunhua County of Hebei Province. Samples were collected from top soil (0~20 cm) of pine forest, grassland, chestnut forest, and slope farmland that had been cultivated for about 6 months and for over 3 years. The results indicated that deforestation and cultivation led to increase in soil bulk density and decrease mostly in soil nutrients. Compared to pine forest, the bulk density value of grassland, 6 months's cultivated land, chestnuts and 3 years cultivated land increased by 13.3%, 14.2%, 27.5% and 39.7%, respectively. Most soil nutrients except available N and available P showed significant differences among different land use types. Soil nutrient contents except total P in chestnuts and over 3 years cultivated soils decreased significantly in comparison with pine forest. Chestnut forest witnessed a decrease in soil organic matter by 60.7%, total N by 35.6%, total K by 21.3% and available K by 57%; while over 3 years cultivated soils saw a decrease in SOM by 62.9%, total N by 52.6%, total K by 31% and available K by 60%. The soil degradation indices showed that grassland and slope farmland cultivated for about 6 months did not degrade significantly, however, a severe degradation occurred to over 3 years's cultivated land and chestnut forest. Obviously, cultivation on steeper slopes results in severe soil degradation and diminishes greatly soil quality. It seems that the development of chestnuts by deforestation is also not a sustainable land use model though more income can be obtained. The soils under chestnuts will subject to severe degradation unless appropriate soil and water conservation practices were conducted.